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River-Therm® Secret Fix System

 River-Therm® is a built-up, site assembled secret fix roofing system with a unique geometric locking action allowing for foot pressure installation. Its incorporated drainage channel enables the manufacture and installation of roof sheets up to 180m in length. On-site mobile production units, craned to roof height, remove the need for end laps on long slopes.


All standing seam and secret fix roofs are designed to breathe through the side lap but this can also be an area of potential water ingress. If the profile becomes submerged the unique River-Therm® drainage channel captures excess water and directs it away from the building to the gutters.

River-Therm® can be rolled on site reducing the need for expensive ridge details and internal gutters, both potential areas for the ingress of water.

River-Therm® has been designed and tested to be installed at roof pitches lower than the industry norm of 4° after deflection.

Low pitch and/or large radius roofs are possible with single length panels, either factory or site rolled, to suit the project's requirements. River-Therm® can be used on roofs with pitches of 1° after steelwork deflection at panel ends.

River-Therm®, as well as the CA 32 1000RL Liner Panel as a standalone element, has been tested for Non-Fragility in accordance with ACR[M]001:2011 ‘Test for Non-Fragility of Profiled Sheeted and Large Element Roofing Assemblies (Fourth Edition)’ achieving a Class B Certification for the complete assembly.

The River-Therm® system is simple to install, with no heavy individual components, reducing manual handling risks, both on the ground and at height.

Based on current building regulations to meet the minimum backstop U-values, the build-up depth for the River-Therm® system is: River-Therm® roof CA 32 1000RL – 0.24W/m²K – 195mm cavity + 43mm external profile = 238mm.

As standard the system is available in Colorcoat HPS200 Ultra® and Colorcoat Prisma® steel or mill finish, stucco embossed and PVDF coated aluminium. As well as the standard material options the system can also be supplied in stainless steel, copper and zinc.

Rolling at eaves, using CA Group's mobile roll forming unit, allows any length of sheet. This is limited only by the length of the steel coil. Minimal handling processes reduce the risk of damage.

Primarily used when crane use is restricted preventing eaves rolling. Ramps are low cost and widely available.

Rolling at ground level using the CA Group's mobile production unit is a good solution for projects requiring lengths too long for factory production, or where the project size would mean numerous deliveries to site with associated transport costs.

Panels manufactured in our factory are ideal for smaller projects with only space for transport and offloading required.

The metal liners used in the system have enough flexibility to follow variations in steelwork making it easier for the cladding contractor to effect a seal. With the fixings and sealing methods adopted on the River-Therm® system achieving results as low as 0.99m³/hr/m² @ 50Pa.

Based on standard U-values the River-Therm® system achieves the following weighted sound reduction figures without any enhancements; River-Therm® roof 0.7mm liner – 45dB

The installed liner panel provides an efficient air barrier, with air permeability tests of 0.99m³/hr/m² @ 50Pa achieved. The Therma-quilt insulation has every fibre coated with silicone to ensure that any moisture in the cavity is not absorbed and is shed to the liner where it is either dissipated or directed away from the building via the gutter.

River-Therm® has been tested by BRE Loss Prevention Certification Board to LPS 1181 Part 1 achieving ‘EXT-B’ classification as standard. The insulation used in the system is also tested to BS 476 and is classified as non-combustible in its own right.

CA Building Products offers full system guarantees for up to 25 years on River-Therm®. This covers the manufacture and design of the whole system including all of the components supplied by CA Building Products (screws, sealants, insulation, spacers, etc). Confidex® Guarantees from Tata Steel for up to 40 years are also available when the system is specified with Colorcoat HPS200 Ultra® and/or Colorcoat Prisma®.

Therma-quilt is a non-hygroscopic glasswool with individual fibres coated with silicone to prevent moisture retention. Therma-quilt is produced from fine, non-combustible glass mineral wool (as defined in BS 3533: 1981), bonded with a thermo-setting resin. Therma-quilt is made from natural materials and recycled glass and is free from CFC, HCFC Volatile Organic Compounds (VOCs). Therma-quilt does not rot, degrade or sustain vermin and will not encourage the growth of mould, bacteria or fungi. Therma-quilt insulation has also been assessed by the LPCB and classified “non-combustible” in its own right.

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